In the combustion of a fuel, such as coal, oil, peat, waste, etc., in a combustion plant, such as a power plant, a hot process gas is generated, such process gas containing, among other components, water vapour, nitrogen, and carbon dioxide, CO2.
In view of the increasing environmental concerns in connection with the release of carbon dioxide to the atmosphere several systems for removing carbon dioxide from process gas have been proposed. One such system is disclosed in U.S. Pat. No. 6,755,892. The system of U.S. Pat. No. 6,755,892 comprises two parallel sorbent beds, each of which is provided with a sorbent. Carbon dioxide is captured, at a low temperature, in one of the beds, while the other bed is regenerated, at a high temperature, to release carbon dioxide which may subsequently be forwarded to a carbon dioxide storage facility. However, high-pressure drop over the sorbent beds, and poor CO2 removal efficiency makes the system of U.S. Pat. No. 6,755,892 less efficient in applications of higher gas flow rates, such as those of power stations, such as for example coal-fired power stations, in which there is a high CO2 concentration in the process gas and a high gas flow rate.